Monday, June 20, 2011

20



D40, Lens Baby with 1.6x attachment.

Sunday, June 19, 2011

19



D40, 60mm f/2.8 AF-S, Harpo.

Saturday, June 18, 2011

18



D40, Lens Baby with 1.6x attachment.

Friday, June 17, 2011

17



I have no idea what this means, and Google didn't seem to know either.

D40, Lens Baby with 1.6x attachment

Thursday, June 16, 2011

16



D40, Lens Baby and 1.6x attachment.

Wednesday, June 15, 2011

15



D40, Lensbaby with 1.6x attachment.

Tuesday, June 14, 2011

14



Lens Baby with 1.6x attachment.

Monday, June 13, 2011

13



I...don't know. Will have to go back when there is better light.

D40, 60mm f/2.8 AF-S.

Sunday, June 12, 2011

Saturday, June 11, 2011

11



Pi?

D40, 60mm f/2.8 AF-S.

Thursday, June 9, 2011

More depth of field and perspective fun.

First, trying to match framing with different focal lengths.

28mm @ f/5.6


50mm @f/5.6


85mm @ f/5.6


105mm @ f/5.6


200mm f/4 @ f/5.6


What if we try to minimize depth of field? These are all shot wide open. Some of these lenses (esp. the 50mm) really do better stopped down a little. Although the 50 is still sharp in the center if you nail the focus.

28mm f/2.8 @ f/2.8


50mm f/1.4 @ f/1.4


85 f/1.8 @ f/1.8


105mm f/2.8 @ f/2.8


200mm f/4 @ f/4


Either the 85 or the 200 win at depth of field isolation, at least for this subject. Technically you can figure out the theoretical aperture opening of each lens (focal length over f/stop), which is supposed to also relate to how out of focus the background gets, but this does not account for moving to preserve framing, only the relative depth of field if we were shooting without moving.

Lens: 28mm f/2.8 Lens opening: 10mm
Lens: 50mm f/1.4 Lens opening: 35.7mm
Lens: 85mm f/1.8 Lens opening: 47.2mm
Lens: 105mm f/2.8 Lens opening: 37.5mm
Lens: 200mm f/4 Lens opening: 50mm

I'd say the empirical data agrees, the 50mm and 105mm have similar sized blur circles wide open, and ditto for the 85mm and 200mm, despite the 85mm being around 10 feet from the subject where the 200mm was 20+ feet from the subject. Here are some crops. I don't think I can say for sure if there is a difference. It doesn't help the background has changed, and the character of the out of focus backgrounds might change ones impression, my focus and exposure, etc. I think the background of the 200mm might be slightly more out of focus?

85mm f/1.8 cropped:


200mm f/4 cropped:


And...

50mm f/1.4 cropped:


105mm f/2.8 cropped:


I guess the 50mm f/1.4 won't win any bokeh beauty contests wide open. The 200mm makes all the rest look bad wide open!

For fun, here are some of the fastest Nikon lenses, which should have some of the greatest depth of field isolation (not counting the super telephotos...)

Lens: 50mm f/1.2 Lens opening: 41.6mm
Lens: 85mm f/1.4 Lens opening: 60.7mm
Lens: 105mm f/1.8 Lens opening: 58.3mm
Lens: 135mm f/2 Lens opening: 67.5mm
Lens: 180mm f/2.8 Lens opening: 64.3mm
Lens: 200mm f/2 Lens opening: 100mm (!)

Of course, to really control depth of field you need a tilt-shift lens or a large format camera...

Moral of this story: depth of field and perspective are kinda complicated. The basic ideas are certainly easy: long lens, faster f/stop, closer subject mean less depth of field, but when you start to change multiple things I think it is hard to predict the results. Also, it is fun to take pictures of stuff.

Wednesday, June 8, 2011

Tuesday, June 7, 2011

Field of View and Depth of Field

Just mucking about a bit.

First off: field of view. Taken with my D40 (approx 1.5x crop factor) on tripod, so camera is stationary between shots. I know I overuse Mr. Washington here, but he's a nice subject and very patient. My exposures and focus could be more consistent, I wager.

28mm f/2.8 @ f/5.6


50mm f/1.4 @ f/5.6


85mm f/1.8 @ f/5.6


105mm f/2.8 @ f/5.6


200mm f/4 @ f/5.6


So what if you take a wider angle lens and crop? You get the same perspective as a longer lens, but what happens to depth of field?

28mm f/2.8 @ f/5.6 cropped (note we are at like a 200% view -- this lens is sharper than it appears)


50mm f/1.4 @ f/5.6 cropped


85mm f/1.8 @ 5.6 cropped


105mm f/2.8 @ f/5.6 cropped


For reference, here's the 200mm f/4 @ 5.6 again:



So this is a well known phenomenon, but one that still surprises me. The same thing would happen if I compare a 50mm lens on my D40 to a 75mm lens on my full frame FM, shooting from the same position and aperture I would get the same perspective, but the depth of field would be greater for the 50mm lens.

For a much fancier lens simulator, check this out:
Nikon's lens simulator

7



Sometimes I cannot translate a photo to black and white in a satisfactory manner. This is an example.

D40, 60mm f/2.8 AF-S.

Monday, June 6, 2011

Sunday, June 5, 2011

Saturday, June 4, 2011

Friday, June 3, 2011

3



Nikon FM, 50mm f/1.4 around f/2, old Kodak Gold 200

Thursday, June 2, 2011

Voigtlander 75mm f/2.5 Color Heliar (Leica Screw Mount)

I'd be remiss if I did not talk about this cute little lens. There are not very many reviews (although soundvisionpassion has a very nice one) of it out there...




Filter size: 43mm (I've adapted this to 46mm)
Close focus distance: 1 meter or 3.3 feet.
Aperture range: f/2.5 - f/16, click stops every half stop
Aperture blades: 10
Depth of field scale for f/4, f/8, f/11 (ticks but not labeled), and f/16





































This lens is great.

It seems plenty sharp for me, (modulo the difficulties of getting accurate focus from a rangefinder when focusing close with fast lenses, especially since I am using it with an external finder, which will probably cause me to shift the distance from the camera to the subject slightly unless I am using a tripod).  I am thankful that Voigtlander offers inexpensive alternatives to expensive Leitz lenses.

It is a small lens, but well made, with a satisfying heft. It includes a screw-in hood and a nice slip-on, felt-lined aluminum lens cap. Focus is smooth and well damped like my favorite AI/AI-S Nikkors.  I wish it took 46mm filters.  I bought a 43mm - 46mm adapter for mine.  Half stop clicks on the aperture sort of annoy me.

This lens was discontinued with the introduction of the 75mm f/1.8 (Leica M-mount only), so if you think you might be interested in an inexpensive, tiny medium telephoto for your screw mount Leica (or M or NEX via adapter), you might want to pick one of these up before they become unavailable.  That said, the 90mm f/3.5 APO is a more standard focal length for Leica lenses.

Other resources
CameraQuest
Tested on a Sony NEX

More photos from this lens